1. Symptom identification:
① Radiation -like cracks. With the centered on the fruit, it extends to the shoulder and is radial -shaped deeply. It can start from the green maturity period of the fruit. Simple stripes cracking near the fruit titter, 2-3 days before the color rotation, the cracks are obvious.
② Circle cracking fruit. With the fruits as a round heart, it is shallow in ring -shaped, and most of them appear in the fruit maturity.
③ striped cracks. At the part of the fruit peak, it cracks irregular stripes.
2. The main cause and the condition conditions
① In the later period of fruit development or during the transition period, encountering high temperature, scorching sun, drought, excessive water, etc. in summer, the skin's epidermis is thin, the flesh has a lot of moisture content, the growth rate of the peel is increasing with the growth and expansion of the pulp tissue, the increased pressure increase is increased, and the pressure pressure increases Great cracking phenomenon.
② During the growth of fruits, the supply of soil moisture is uneven, which is the main reason for cracking fruit. However, there are different varieties, and the resistance to cracking fruits is also different. Generally, small fruit types with small and shallow pipes are generally fruitful. Or large leaves and thin layers of peels are strong.
③ Under low temperature conditions, especially in winter warm shed tomatoes, the pollination of the flower wares is not sootic to crack in the chop of the flower columns
open.
④ High temperature or low temperature affects the absorption of calcium and boron elements of tomatoes, which is the main cause of cracking. After calcium absorption, calcium oxalic acid in the body of tomato plants forms calcium oxalate. If less calcium is absorbed, oxalic acid will mostly damage the heart leaves and flower buds, leading to cracking fruit.
3. Prevention and control measures
(1) Agricultural prevention and control
① Choose a variety of cracks and lush branches.
② Cultivate strong seedlings. It can effectively enhance tomato resistance, thereby reducing the occurrence of cracking.
③ Strengthen cultivation management, add organic fertilizer, and add phosphorus and potassium fertilizer. Improve the resistance of plants, thereby enhancing crack resistance. At the time of the whole land, 2000-3000 kg of rotten organic fertilizer per acre, 40 kg of overlapping calcium phosphate. When the soil is cultivated, 10 kg of compound fertilizer is applied per acre. Do not put water immediately after application, so that the fertilizers can work when flowing and sitting fruit, so as not to grow long and weaken resistance. Do not apply fast -acting nitrogen fertilizer after the fruit is enlarged.
④ The protection of the protection ground, heat preservation, strengthen ventilation, breathable and timely watering, the water supply is uniform, avoid drought in the early stage, and large water irrigation in the later stage. Entering winter, when the temperature starts to decline, the membrane is kept in time when the temperature is high every day.
⑤ The cultivation of high -temperature scaffolding in summer can be used to reduce the temperature of the field; open the surrounding membranes and top windows to increase ventilation; appropriate sparse planting. Increase transparency.
⑥ Adjust the seeding section to make it miss the low temperature period, thereby avoiding cracks caused by low temperature disorders.
(2) Pharmacy prevention and control
Spray 96 % copper sulfate L000 times or 0.1 % zinc sulfate or O. 7 % calcium chloride, plus O. 1 % borax, once every 10-15 days, spray 2-3 times in a row.
